In the semiconductor manufacturing industry, automated substrate handling systems or cluster platforms move semiconductor units or wafers through a series of process modules. As the wafer moves through the cluster platform, each module performs a particular process on the wafer. Such operations include vapor deposition, etching, and similar processes.
In the industry, minimization of contaminants in the fabrication process is of utmost importance. In order to prevent defects from particulate contaminants, the cluster assembly maintains a vacuumed, “clean” room environment throughout the assembly. Modern process modules and cluster assemblies are likewise designed to minimize particulate generation through millions of cycles of operation. Typical components are designed with minimal moving parts and isolation of moving components to limit generation of particulate matter.
Modern cluster assemblies provide gate valves between process modules. The gate valves serve to allow the process modules to be vacuum sealed and also to control the flow of air or fluid within the cluster assembly. In operation, the gate valves open to allow wafers to be transferred from one process module to another. The gate valves then close to seal off the module to create a sealed, positive-pressure environment during processing.
Present gate valve assemblies must withstand millions of cycles of operation. Similar to the process modules, present gate valves have been designed to limit the generation and introduction of contaminants within the cluster assembly. An exemplar of the prior art is U.S. Pat. No. RE38,318 to Brenes which shows a low profile gate valve with bellows and is incorporated herein by reference.
Modern fabrication plants and cluster assemblies typically run at high capacity and high volume. Thus, although the assemblies and associated components involve many parts moving through millions of cycles, users demand minimal downtime for service and repairs. In the industry, even one hour of downtime to replace worn parts or lubricate components can be costly.
Given the high cost of “clean” room environments, cluster assemblies are further designed to utilize minimal space. Gate valves are therefore situated within tight spaces between process modules. The tight spacing makes present gate valves difficult to reach and routine maintenance and repair even more challenging.
Gate valves, in particular, require periodic servicing of the gate support and valving assembly. Access to present gate valves for service requires disassembly of the gate valve housing and/or portions of the surrounding modules. Given the limited space between modules, the whole gate valve often must be removed from the fabrication line in order to access the inner valve assembly. The repair and service process thus becomes tedious, time-consuming, and expensive.
What is needed is a gate valve which overcomes the above and other disadvantages. What is needed is a gate valve that allows quick access to the gate support and valve components for service.